libzmq/src/select.hpp
Luca Boccassi da31917f4f Relicense from LGPL3 + exceptions to Mozilla Public License version 2.0
Relicense permission collected from all relevant authors as tallied at:
https://github.com/rlenferink/libzmq-relicense/blob/master/checklist.md
The relicense grants are collected under RELICENSE/ and will be moved
to the above repository in a later commit.

Fixes https://github.com/zeromq/libzmq/issues/2376
2023-06-05 20:31:47 +01:00

145 lines
3.4 KiB
C++

/* SPDX-License-Identifier: MPL-2.0 */
#ifndef __ZMQ_SELECT_HPP_INCLUDED__
#define __ZMQ_SELECT_HPP_INCLUDED__
// poller.hpp decides which polling mechanism to use.
#include "poller.hpp"
#if defined ZMQ_IOTHREAD_POLLER_USE_SELECT
#include <stddef.h>
#include <vector>
#include <map>
#if defined ZMQ_HAVE_WINDOWS
#elif defined ZMQ_HAVE_OPENVMS
#include <sys/types.h>
#include <sys/time.h>
#else
#include <sys/select.h>
#endif
#include "ctx.hpp"
#include "fd.hpp"
#include "poller_base.hpp"
namespace zmq
{
struct i_poll_events;
// Implements socket polling mechanism using POSIX.1-2001 select()
// function.
class select_t ZMQ_FINAL : public worker_poller_base_t
{
public:
typedef fd_t handle_t;
select_t (const thread_ctx_t &ctx_);
~select_t () ZMQ_FINAL;
// "poller" concept.
handle_t add_fd (fd_t fd_, zmq::i_poll_events *events_);
void rm_fd (handle_t handle_);
void set_pollin (handle_t handle_);
void reset_pollin (handle_t handle_);
void set_pollout (handle_t handle_);
void reset_pollout (handle_t handle_);
void stop ();
static int max_fds ();
private:
// Main event loop.
void loop () ZMQ_FINAL;
// Internal state.
struct fds_set_t
{
fds_set_t ();
fds_set_t (const fds_set_t &other_);
fds_set_t &operator= (const fds_set_t &other_);
// Convenience method to descriptor from all sets.
void remove_fd (const fd_t &fd_);
fd_set read;
fd_set write;
fd_set error;
};
struct fd_entry_t
{
fd_t fd;
zmq::i_poll_events *events;
};
typedef std::vector<fd_entry_t> fd_entries_t;
void trigger_events (const fd_entries_t &fd_entries_,
const fds_set_t &local_fds_set_,
int event_count_);
struct family_entry_t
{
family_entry_t ();
fd_entries_t fd_entries;
fds_set_t fds_set;
bool has_retired;
};
void select_family_entry (family_entry_t &family_entry_,
int max_fd_,
bool use_timeout_,
struct timeval &tv_);
#if defined ZMQ_HAVE_WINDOWS
typedef std::map<u_short, family_entry_t> family_entries_t;
struct wsa_events_t
{
wsa_events_t ();
~wsa_events_t ();
// read, write, error and readwrite
WSAEVENT events[4];
};
family_entries_t _family_entries;
// See loop for details.
family_entries_t::iterator _current_family_entry_it;
int try_retire_fd_entry (family_entries_t::iterator family_entry_it_,
zmq::fd_t &handle_);
static const size_t fd_family_cache_size = 8;
std::pair<fd_t, u_short> _fd_family_cache[fd_family_cache_size];
u_short get_fd_family (fd_t fd_);
// Socket's family or AF_UNSPEC on error.
static u_short determine_fd_family (fd_t fd_);
#else
// on non-Windows, we can treat all fds as one family
family_entry_t _family_entry;
fd_t _max_fd;
#endif
void cleanup_retired ();
bool cleanup_retired (family_entry_t &family_entry_);
// Checks if an fd_entry_t is retired.
static bool is_retired_fd (const fd_entry_t &entry_);
static fd_entries_t::iterator
find_fd_entry_by_handle (fd_entries_t &fd_entries_, handle_t handle_);
ZMQ_NON_COPYABLE_NOR_MOVABLE (select_t)
};
typedef select_t poller_t;
}
#endif
#endif